Squamous Cell Carcinoma (SCC Horse)
Squamous cell carcinoma (SCC) is a malignant tissue formation (tumor) originating from the superficial layers of the skin and mucous membranes. It is the most common type of eye cancer in horses. This test identifies a gene mutation that increases the risk of developing SCC.
This mutation for SCC has been found in Haflingers and Percherons. The inheritance is autosomal recessive.
Genetic Test: available in Shop
Symptoms
- Slowly growing malignant skin neoplasms.
- Especially mucous membranes are affected.
- Development of eye cancer.
- Impairment or loss of the eye.
General Information
- Most common type of eye cancer in horses.
- This test identifies a gene mutation that increases the risk of developing a SCC. → Risk Test
- Due to this mutation in the DNA, the DDB2 protein, which is responsible for DNA repair in UV light damage, is not correctly formed.
- SCC is particularly common in Haflinger Horses due to the frequent occurrence of this mutation in the breed.
- It has also been described in Belgian draft horses and Pecherons, as well as Rocky Mountain Horses, Connemara ponies, Holsteiners and Belgian Warmbloods.
Breeds affected
Haflinger Horse
Test Information
Genotype and Lab Report
Inheritance: autosomal recessive
→ The risk of developing SCC is increased if both copies of the gene (scc/scc) are affected by the mutation. Animals with only one copy (N/scc) are clinically normal carriers.
Genotyp
N/N = normal
The horse has no copies of the genetic variant causative for SCC and therefore cannot pass it on to its offspring.
N/scc = a carrier
The horse is clinically healthy. The genetic variant causative for CSS will be passed on to its offspring with a probability of 50%.
scc/scc = at risk
The horse has an increased risk of developing SCC. The mutation will be passed on to its offspring with a probability of 100%.
Recommendations
- Carriers may be bred to normal animals (N/scc x N/N) without any risk of producing at risk offspring. The offspring should also be tested before breeding to determine if they are carriers or normal.
- When breeding two carriers (N/scc x N/scc), there is a probability of 25% for each foal to inherit two copies of the mutation (scc/scc) and therefore having an increased risk of developing SCC. This should be taken into consideration when planning breedings.
Literature
Bellone, R.R., Liu, J., Petersen, J.L., Mack, M., Singer-Berk, M., Drögemüller, C., Malvick, J., Wallner, B., Brem, G., Penedo, M.C., Lassaline, M.: A missense mutation in damage-specific DNA binding protein 2 is a genetic risk factor for limbal squamous cell carcinoma in horses. Int J Cancer :, 2017. Pubmed reference: 28425625. DOI: 10.1002/ijc.30744.
Singer-Berk, M., Knickelbein, K.E., Vig, S., Liu, J., Bentley, E., Nunnery, C., Reilly, C., Dwyer, A., Drögemüller, C., Unger, L., Gerber, V., Lassaline, M., Bellone, R.R.: Genetic risk for squamous cell carcinoma of the nictitating membrane parallels that of the limbus in Haflinger horses. Anim Genet :, 2018. Pubmed reference: 29999543. DOI: 10.1111/age.12695.
Further information is available at Online Mendelian Inheritance in Animals.